Friday, December 16, 2011

1121439991.txt

From: Phil Jones <p.jones@uea.ac.uk>
To: Tom Wigley <wigley@cgd.ucar.edu>
Subject: Re: paleoT
Date: Fri Jul 15 11:06:31 2005

Tom,
This Briffa series is just a three site average (trees from Tornetrask, Polar Urals
and
Taimyr) - all in northern Eurasia. It is therefore for a limited region and is likely
just the summer, whereas some of the others have regressed on annual T for
the NH (or north of 20N).
Of these 3, the first two are in most of the other series (Esper, Crowley, Jones, Mann)
and also for HF in Moberg. Not sure whether Taimyr is in any of the others.
Esper uses a different standardization approach, but should have most of the
same trees, but only TRW. The others use our reconstructions which have MXD
is as well.
Have you tried these correlations after extracting the LF trends (say residuals
from a 30 or 50 yr filter)? Would expect some of them to be much, much lower.
Keith's reconstruction that would be much better is the one that goes back to
only about 1400. Do you have this? Go here [1]http://www.ncdc.noaa.gov/paleo/paleo.html
then click on paleo data, then on obtaining and look for Keith's - it says 600 years in
the title. You can get the data.
Cheers
Phil
At 21:57 14/07/2005, you wrote:

Phil,
I eventually refiltered all the paleo data and have compared these
with likewise filtered MAGICC output. Very interesting results.
Can you comment, off the record, on Keith's paleo series.
Here are correlations of individual series against the 7 series average.
(Different series lengths, but essentially same results over common lengths.)
SERIES 1000-1610 1610-1995 1000-1995
Briffa -.272 .262 .207
Esper .583 .917 .687
Crowley .879 .946 .902
Jones .773 .917 .861
Mann .760 .856 .822
M&J-NH .929 .965 .936
Moberg .904 .856 .871
Correlations with the climate model are not the same -- but Briffa is
again the clear outlier.
Why?
Tom.

Prof. Phil Jones
Climatic Research Unit Telephone +44 (0) 1603 592090
School of Environmental Sciences Fax +44 (0) 1603 507784
University of East Anglia
Norwich Email p.jones@uea.ac.uk
NR4 7TJ
UK
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References

1. http://www.ncdc.noaa.gov/paleo/paleo.html

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